As a material which is excellent in heat resistance and abrasion resistance, which is light in weight and which is suitable as a slide material for a brake, a metal composite material prepared by impregnating a preliminary molded product of ceramic fibers or carbon fibers, or ceramic particles or carbon particles with a metal titanium powder, with aluminum or an aluminum alloy by molten metal forging, has been known (for example, Patent Document 1). Such a metal composite material has hardness and a moderate coefficient of friction in addition to the above characteristics, and thus it has characteristics required for a slide material for a brake so far.
On the other hand, in recent years, higher levels of performance and quality are required for a slide material for a brake in view of the safety and speeding up of automobiles, vehicles, etc., and stricter characteristics are required also for the above metal composite material. Further a material which is lighter in weight and has higher strength, and which has a high thermal conductivity, has been expected.
However, with respect to a conventional metal composite material, reduction in weight and further improvement in strength, the thermal conductivity, etc., are considered to be difficult from limitations of the ceramic fibers, the carbon fibers or the like for reinforcing. Further, since metal titanium is mixed with ceramic fibers, carbon fibers or the like for reinforcing (hereinafter referred to as reinforcing fibers or the like) to form a molded product, which is pressure impregnated with aluminum or an aluminum alloy by molten metal forging, miscibility of the reinforcing fibers or the like with metal titanium and wettability with an aluminum alloy or the like as the matrix are not sufficiently satisfactory. As a result, the above metal composite material has a problem such as low uniformity of the quality, in addition to the low miscibility with metal titanium at the time of production and low impregnation properties with the aluminum alloy or the like in the molten metal forging.
Patent Document 1. JP-A-2003-49252